From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D0570C433DF for ; Tue, 30 Jun 2020 07:57:42 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A5BF82067D for ; Tue, 30 Jun 2020 07:57:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A5BF82067D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jqB8x-0000QH-62; Tue, 30 Jun 2020 07:57:27 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jqB8w-0000QC-EU for xen-devel@lists.xenproject.org; Tue, 30 Jun 2020 07:57:26 +0000 X-Inumbo-ID: 55448dc6-baa7-11ea-85d4-12813bfff9fa Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 55448dc6-baa7-11ea-85d4-12813bfff9fa; Tue, 30 Jun 2020 07:57:24 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id B7D77AAC3; Tue, 30 Jun 2020 07:57:23 +0000 (UTC) Subject: Re: [PATCH 1/2] xen/displif: Protocol version 2 To: Oleksandr Andrushchenko , Oleksandr Andrushchenko , "xen-devel@lists.xenproject.org" , "ian.jackson@eu.citrix.com" , "wl@xen.org" , "konrad.wilk@oracle.com" References: <20200520090425.28558-1-andr2000@gmail.com> <20200520090425.28558-2-andr2000@gmail.com> <84d975e3-0cea-becb-f505-856368a63fb7@suse.com> <80bfd713-9556-42d7-6bf7-dee85fdf8c10@gmail.com> <9150a2ad-7c08-1f93-674a-963341bf0ece@suse.com> <24252f32-ef40-0daf-a585-36cb00f149d0@epam.com> From: =?UTF-8?B?SsO8cmdlbiBHcm/Dnw==?= Message-ID: Date: Tue, 30 Jun 2020 09:57:23 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.9.0 MIME-Version: 1.0 In-Reply-To: <24252f32-ef40-0daf-a585-36cb00f149d0@epam.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" On 30.06.20 09:39, Oleksandr Andrushchenko wrote: > On 6/30/20 10:30 AM, Jürgen Groß wrote: >> On 30.06.20 09:09, Oleksandr Andrushchenko wrote: >>> On 6/30/20 10:03 AM, Jürgen Groß wrote: >>>> On 30.06.20 08:13, Oleksandr Andrushchenko wrote: >>>>> On 6/29/20 10:02 AM, Jürgen Groß wrote: >>>>>> On 20.05.20 11:04, Oleksandr Andrushchenko wrote: >>>>>>> From: Oleksandr Andrushchenko >>>>>>> >>>>>>> 1. Change protocol version from string to integer >>>>>>> >>>>>>> Version string, which is in fact an integer, is hard to handle in the >>>>>>> code that supports different protocol versions. To simplify that >>>>>>> make the version an integer. >>>>>>> >>>>>>> 2. Pass buffer offset with XENDISPL_OP_DBUF_CREATE >>>>>>> >>>>>>> There are cases when display data buffer is created with non-zero >>>>>>> offset to the data start. Handle such cases and provide that offset >>>>>>> while creating a display buffer. >>>>>>> >>>>>>> 3. Add XENDISPL_OP_GET_EDID command >>>>>>> >>>>>>> Add an optional request for reading Extended Display Identification >>>>>>> Data (EDID) structure which allows better configuration of the >>>>>>> display connectors over the configuration set in XenStore. >>>>>>> With this change connectors may have multiple resolutions defined >>>>>>> with respect to detailed timing definitions and additional properties >>>>>>> normally provided by displays. >>>>>>> >>>>>>> If this request is not supported by the backend then visible area >>>>>>> is defined by the relevant XenStore's "resolution" property. >>>>>>> >>>>>>> If backend provides extended display identification data (EDID) with >>>>>>> XENDISPL_OP_GET_EDID request then EDID values must take precedence >>>>>>> over the resolutions defined in XenStore. >>>>>>> >>>>>>> 4. Bump protocol version to 2. >>>>>>> >>>>>>> Signed-off-by: Oleksandr Andrushchenko >>>>>>> --- >>>>>>>    xen/include/public/io/displif.h | 83 +++++++++++++++++++++++++++++++-- >>>>>>>    1 file changed, 80 insertions(+), 3 deletions(-) >>>>>>> >>>>>>> diff --git a/xen/include/public/io/displif.h b/xen/include/public/io/displif.h >>>>>>> index cc5de9cb1f35..4d43ba5078c8 100644 >>>>>>> --- a/xen/include/public/io/displif.h >>>>>>> +++ b/xen/include/public/io/displif.h >>>>>>> @@ -38,7 +38,7 @@ >>>>>>>     *                           Protocol version >>>>>>> ****************************************************************************** >>>>>>>     */ >>>>>>> -#define XENDISPL_PROTOCOL_VERSION     "1" >>>>>>> +#define XENDISPL_PROTOCOL_VERSION     2 >>>>>> >>>>>> This is not very nice regarding compatibility. >>>>>> >>>>>> Can't you add a new macro for the integer value? >>>>> >>>>> We can leave it as is, e.g. define XENDISPL_PROTOCOL_VERSION as "2", >>>>> >>>>> so we do not break the existing users. Then if every user of the header has >>>>> >>>>> its local copy (this is what we now use in the display backend), then that >>>>> local copy can be changed in a way suitable for the concrete user, e.g. "2" >>>>> >>>>> redefined to 2. This cannot be done (?) for the Linux Kernel though. >>>>> >>>>> Or we can have >>>>> >>>>> #define XENDISPL_PROTOCOL_VERSION     "2" >>>>> >>>>> #define XENDISPL_PROTOCOL_VERSION_INT  2 >>>>> >>>>> Jurgen, what's your preference here? >>>> >>>> I would prefer the latter, as it avoids the need to modify the header >>>> when copying it to a local project. >>>> >>> Ok, I'll have 2 definitions then >>> >>> Anything else (beside the comments on new functionality) I can add/change >>> >>> before sending v2 of the patch? >> >> I would have said so. :-) > > Thank you, > > the series also has a patch for libgnttab. Do you want me to send the protocol patch > > separately or should we wait for Ian and Wei to review? These changes are related, > > thus I sent then togheter This is something to ask the tools maintainers IMO. Juergen